Defaults were the 📝subreddits to which new 📝Reddit users are subscribed. Up to May 2017, these subreddits were chosen by 📝Administrators based on content and activity, but changes to Reddit's architecture discontinued this practice with the development of /r/popular.
Retiring the defaults decreases the monopoly default subreddits maintain on popularity and voting, giving more attention to previously smaller and more niche subreddits.
References
- Testing a New Sign Up Experience, reddit.com
- Default Subreddits Are Over. How Will This Affect Community Dynamics, reddit.com